Nonmetallic bottle cap



Dec. 27, 1938. s. H. A. YOUNG NONMETALL I C BOTTLE CA P Filed Jan. 15, 1937 2 Sheets-Sheet 1 5mm HAY INVENTOR. g

A TORNEYS.

1938- s. H. A. YOUNG 2,141,834

NONMETALLIC BOTTLE CAP Filed Jan.-l5, 1937 2 Sheets-Sheet 2 v IIV VENTOR.

A TTORNEYS.

Patented Dec. 27, 1938 I PATENT OFFIE 2,141,834 NONME'IPAIIIJLMI, BOTTHE CAP Serenus H. A. Young, St. Paul,

Minn, assig'l or to Young Engineering Laboratories, Inc., Minneapolis, Minn, a corporation of Minnesota Application January 15, 1937, Serial No. 120,717

4 Claims.

My invention relates to an improvement in bottle caps of a type particularly designed for use in covering milk bottles and the like. My

cap is provided with a skirt portion adapted to extend down over the pouring lip of the bottle.

Plaits or folds are provided in this skirt portion to restrict the diameter thereof, and to cause this portion to fit closely about the pouring lip of the bottle.

It is an object of my invention to provide a cap formed of paper or other suitable material, having a coating thereon of a material capable of acting as a bonding agent. This bonding agent is capable of adhering to itself or among other 5 surfaces, to those which have a wax coating or impregnation, or to paper surfaces. This coating permits the skirt of the cap to be folded in a series of plaits which remain in folded form when once folded for locking the cap securely in position on the bottle without adhering the cap to the bottle.

It is an object of my invention to provide a series of tabs forming the skirt portion of the cap. These tabs are-ordinarily .connected by folds and overlap to some extent. The bondin agent within; the folds tends to hold the folds in closed position. However, in order to seal the folds closed, a portion of each fold between overlapping tabs is cut away to permit the over- 0 lapping portion of one tab to seal directly to the tab overlapped.

In the past pressure sensitive adhesives, temperature sensitive adhesives, and water soluble adhesives have been used for sealing purposes.

a Pressure sensitive adhesives however, are normally tacky and can not well be used on caps which must be contained in superimposed relationship. Furthermore, such tacky adhesives foul the bottle top making cleaning of the bottles dimcult. Where temperature sensitive adhesives are-used, the folds must be held in folded position by some physical means until the adhesive temperature drops sumciently to solidify the same. Where water soluble adhesives are used,

the caps adhere to wet surfaces such as the pouring lip. Furthermore, the high moisture content of the milk would soften such adhesives used on bottle caps. Each of the adhesives formerly used accordingly possess undesirable so qualities,

Itis the purpose of my invention to provide a thermoplastic coating formed by combining rubber and wax in suitable proportions. The cap [provided with such a coating composition will readily seal in the presence of moisture to lock the bottle cap in position. when this composition is used, the cap may be applied by pressure or temperature, or by a combination of both. The bonding agent is not tacky at normal temperatures and will not crack or separate itself from the base material of the cap when it is folded 180 into plaits. As such material is not moisture absorbent the formation of a plug or pad of cream on the cap will be avoided. The coating will also act as a gasket to prevent leakage of moisture.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of my specification:

Figure 1 is a perspective view of my milk bottle cap in position on the top of a bottle.

Figure 2 is a plan view of the blank from which my cap is formed.

Figure 3 is a plan view of a modified form of blank construction for forming a slightly different type of blank.

Figure 4 is a plan view of a modified form of blank construction.

Figure 5 is a plan view form of blank.

Figure 6 is a side having a plug cap adhered to thereof.

Figure 7 is a view similar to Figure 6 showing a plug cap adhered to the lower surface of a cap blank.

Figure 8 is an enlarged section illustrating the manner in which the coating on the inside face of the cap acts as a gasket between the cap and surface on the bottle.

Figure 9 illustrates a side view of a blank before the coating is added thereto.

Figure 10 illustrates the blank shown in Figure 9 having a coating of suitable thermoplastic composition on one side thereof.

Figure 11 illustrates the blank shown in Figure 9 impregnated with wax on either side thereof.

Figure 12 discloses the wax impregnated blank of Figure 11 having a surface coating of thermoplastic composition thereon.

Figure 13 illustrates a blank as shown in Figure 9 with an adhesive coating on one side thereof and a war; impregnated surface on the other side of the same.

' Figure 14 discloses a cap blank'having a surface of suitable thermoplastic composition on either side thereof.

Figure 15 illustrates a blank formed as shown of another modified elevation view of a blank the upper surface in Figure 12 having a coating of dusting material on the thermoplastic coating thereof to prevent adhering of superimposed blanks.

Figure 16 illustrates in section, my cap as formed in readiness for being applied to a bottle.

Figure 17 illustrates my cap in cross-section applied to a bottle.

Figure 18 illustrates in section my cap of the type disclosed in Figure 7 applied to a bottle.

Figure 19 illustrates a cap of slightly different form applied to the neck of a bottle.

Figure 20 illustrates in enlarged form, the manner in which the tabs forming the cap are adhered together.

My cap A is formed of a blank of prepared paper or the like. This blank to is formed as illustrated in Figure 2 of the drawings. The blank it? is substantially circular in shape, and comprises a central bottle mouth covering portion it, and a skirt l2 adapted to be folded with a series of plaits over the pouring lip of the bot-' tle B. In the preferred form illustrated in Figures l and 2, the plaits are formed by a seriesof equally spaced fold lines i5 and 18, which do not extend radially, but extend so that each line, if extended, would be tangent to a circle i3 concentric with the cap blank iii. A notch M is provided adjacent each of the fold lines l5, at the lower end of each pleat ll this notch it being at its widest point a width equal to the difference between the actual width of the blank between plaits at this point, and the width of an equal angular segment of the bottle neck at this point.

In other words, the fold lines 15 and i8 divide the blank into a series of segments l9 and pleats ll. At the outer extremity of the blank, these segments are substantially wider than necessary to encircle the bottle at the base of the rim or head 16 thereof. The skirt portion E2 of the cap ID must be plaited or folded to fit tightly against the bottle. The notches i l extend the width of the pleats ll between the fold lines it and the fold lines l8. The outer extremity of each segment ill is cut to provide a continuous circular line it about the bottle when the cap is in proper sealed position as shown in Figure l.

When the cap A is in place upon the bottle B, the segments are wrapped spirally down over the bottle pouring lip and rim of the bottle, this spiral wrapping assisting in keeping the segments smooth. The folds ll adhere together in a manner which will be later set forth in detail, the notches i4 permitting the inner surface of a portion of each segment iii to directly contact a portion of the outer surface of the next adjacent segment.

In Figure 3 I illustrate a blank for a cap being substantially similar in shape to the blank of the cap A, This cap is provided with a central mouth covering portion 26 and a skirt portion 22. The skirt 22 is provided with tending fold lines 2'! extending to the outer periphery of the blank. The skirt between the fold lines 2! is divided intoa segment portion 26 and a pleat portion 25, the pleat portion 25- being bounded by fold lines 27 on the sides Notches 28 extend the width of the pleat portions 25 to permit a portion of the inner surface of each segment portion 24 to contact directly the cor responding portion of the outer surface of the next adjacent segment portion 261. In this construction, additional fold lines or corrugations 29 may be provided centrally in each segment portion 2 to compensate for any excessive paper a series of radially ex-.

greases at the point where the cap extends over the pouring lip of the bottle B. These folds 29 act to reinforce the cap, and act as leader plaits to cause the folding of the paper along these lines when the central portion of the cap is drawn into the neck of the bottle.

Figure 4 shows a slightly different form of construction. In this figure, a blank for a cap D is provided having a central bottle mouth covering portion 30 and a skirt portion 32. The skirt 32 is folded to provide a series of segments 33 and a series of connecting-plaits t l, boundedby fold lines 35 and 36. Openings 3? are provided through the folds or plaits 34 to permit the inner surface of one segment to contact a portion of the outer surface of the next adjacent segment 33.

In the usual form, the blank, such as i0 is provided with a plug cap 38 adhered to one surface thereof to seal the top of the bottle. The cap 38 may be adhered to the upper surface of the cap blank, as illustrated in Figure 6, or may be secured to ure 7.

The blank ID is provided with a coating of a suitable thermoplastic composition 40 as illustrated in Figure of the drawings.

In preparing the paper for formation of the cap blank, wax or other waterproofing material is usually impregnated into both surfaces of the blank, as shown in Figure 11 of the drawings. Upon this blank having wax impregnation 39 therein, I provide a coating 40 of thermoplastic sealing material. This material is formed of a composition which will be later described which will seal to the bottle only under elevated temperature or pressure.

As the film coating of thermoplastic composition will adhere to waxy surfaces, it may beonly desirable to coat one side of the paper with the thermoplastic composition film if the paper is impregnated with wax. Figure 12 shows a wax impregnated paper having a coating of the thermoplastic composition film on one side only. This film could just as well be on both sides in this form. Figure 13 shows a film coating on one side of a paper, with a wax impregnation on the other side. Figure 14 shows a paper coated with the thermoplastic composition film on both sides. In Figure the paper is im pregnated with wax and is provided with a thermoplastic composition film of coating. A protective coating of starch, flour, or other harmless material may be provided, as at' lz, to prevent A in section in partially formed state in which it is made and shipped for use in the capping operation. In this figure in dotted outline may'be seen a series of superimposed caps A, showing the manner in which the caps may be stacked. The skirt portion l2 of the cap A is projecting downwardly from the central portion M thereof in a truncated conical formation, and the plaits or folds are in partially folded position.

In Figure 1'? the cap A is shown in section in engagement with the top of a bottle B. The

the bottom thereof, as shown in Fig-v The skirt i2 is wrapped tightly about the rim it.

of the bottle B, the skirt being formed in a series of plaits or folds as described. Each segment l9 overlaps the next adjacent tab and is adhered thereto, in the manner illustrated in Figure 1,

and in enlarged form in Figure 20. When in this position, the coating on the under surface of the blank forms a tight seal against the bottle acting as a gasket in the manner illustrated in Figure 8..

A similar construction is shown in Figure 18, with the exception that the plug cap 38 is formed on the under side of the blank, rather than on the top side. With this exception, the caps of Figures 17 and 18 are alike.

Figure 19 is similar to that of Figures 1'? and 18, but in this figure the blank is stretched taut across the top of the bottle, and no plug cap such as in Figures 1'? and 18 is used. In the construction of Figure 19, the folds hold the cap upon the top of the bottle, and the thermoplastic composition film on the inside of the cap provides a gasket for the sealing of the cap upon the bottle top.

The cap illustrated in Figure 5 differs from the other caps in that it is provided only with an annular ring of bonding material 11 extending peripherally about the same. in a series of segments 18 in the skirt I9, each segment being bounded by a substantially radially extending line and a projecting portion 82 which is formed to overlap the next adjacent segment and to adhere thereto.

The coating of thermoplastic composition which I have described to some extent, is preferably formed of paraffin wax and rubber as disclosed in U. S. Patent No. 2,054,112 and No. 2,054,113. The parafiin wax has a melting point between and F. and comprises from 70 to 94% of the solution. The rubber used may include india rubber or Hevea rubber, gutta rubber, and their natural or synthetic equivalents for the purpose of this invention, singlyor mixtures thereof. The term india-rubber may include pale crepe rubber, smoke sheet rubber, synthetic rubber, artificial gummy substances and polymers. The term wax may include the use of paramn wax, beeswax, spermaceti, candelillag, carnauba, amorphous waxes and other natural or synthetic waxes.

In forming the adhesive, the wax is melted by heating to a temperature of from 180 F. to 220 F The rubber is then added in small pieces torn from thin sheets or in a shredded or otherwise subdivided form. The addition of the rubber reduces the temperature which should be allowed to drop to around 180 F. and thereafter be maintained between and F. until the rubber is thoroughly dissolved. It is desirable to keep the temperature of the mixture at about the temperatures indicated, to avoid over heating which results in an undesirable darkening of the mass and an undesirable odor.

After the rubber has been in the paramn wax for about an hour, the pieces of rubber are sumciently softened and swollen to permit complete disintegration by agitation. With an ordinary revolving blade stirrer, it requires 5 to 6 hours to produce a smooth solution of the rubber and paraifin wax, but with equipment especially de- This cap is formed signed for this work the time can be materially reduced.

In compositions of this adhesive up to about 30% by weight of pale crepe rubber, at which percentage the viscosity becomes too great, the oohesiveness of the mixture and its adhesiveness as a coating increase with the viscosity of the mixture. It is therefore important not to lower the viscosity of any given mixture unnecessarily as by increasing the temperature or time of heating of the ingredients when dissolving the rubber in the paraffin wax. The viscosity for a given concentration of rubber in wax decreases with the time of heating.

milling the rubber used in the mixture. With the given concentration of rubber in wax very small percentages of a rubber accelerator, such as mercaptobenzothiazol, will markedly reduce the viscosity. The eifect of this accelerator is dependent upon the specific accelerator used and the percentage added. With a given concentrationof rubber in wax, vulcanizing agents (such as sulphur chloride) reduce the viscosity. The addition of anti-oxidants, such as symmetrical dibetanaphthyl-p-phenylene diamine, has little eifect on the viscosity.

Additional visosity may be obtained in a parafiin wax mixture by the use of other materials .35 resultant mixture is less effective as an adhesive than rubber, such as aluminum stearate, but the and a moisture-proofing.

The minimum heat and time required to make a suitable heat seal with my composition will vary slightly with the composition of the mixture. If it contains, for example, 12% of pale crepe rubber, it will seal in not over 3 seconds at a temperature of 300 F. to 500 F. depending upon the thickness of the paper to which the seal is being made. I have foundthatsatisfactory. seals may be made at temperatures ranging from 200' F. to 500 F.

The thermoplastic composition thus provided has benefits of particular advantage for use on bottle caps. Thin paper coated with this material may be folded 180 F. without cracking or breaking the waterproof film. The thermoplastic composition is readily removed by caustic cleaning solutions ordinarily used in creameries. Furthermore, the specific composition has an ex tremely important quality of adhering in the presence of moisture. This last feature makes a construction which is decidedly advantageous over prior types of caps.

Milk bottles are ordinarily washed with hot My composition will seal properly in the presence of this moisture. Often moisture is applied to the caps before the caps are put on the bottles in order to prevent too tight a seal between the cap and the bottle. In constructions where plug caps are used, the seal is mainly effected by the central depressed portion of the cap. The moisture on the lip provides a con rol for the degree of sealing of the cap,

In accordance with the patent statutes, I have described the plans of operation and construction of my bottle cap and while I have endeavored to set forth the best embodiments thereof, I desire to have it understood that this is only a means of carrying out my invention and that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A cap for bottles and other containers formed of light foldable sheet material, a coating of thermoplastic composition on the inner face of said cap adapted to be placed in contact with the mouth of a container, said cap having a central mouth covering portion and a skirt portion, a series of spaced substantially radially extending fold lines in said skirt portion adapted to enable same to forma series of segments and connecting pleats, a portion of each of said pleats being cut out thereby permitting a portion of the inner coated face of each segment to be folded over in direct contact with the corresponding portion of the outer surface of the next adjacent segment portion and tobe adhered thereto by heat and pressure, and the inner coated face of each pleat being adapted to be folded over in direct contact with the corresponding inner coated surface of the next adjacent segment portion and adhered thereto by heat and pressure.

2. A cap for bottles and other containers formed of a light foldable sheet material, a coating of thermoplastic composition on the inner face of said cap adapted to be placed in contact with the mouth of a container, said cap having a central mouth covering portion and a skirt portion, a series of spaced substantially radially extending fold lines in said skirt portion adapted to enable same to form a series of segments and connecting pleats,- the lower end portion of said pleats being cut to form notches thereby permitting a portion of the inner coated face of each segment to be folded over in direct contact with the corresponding portion of the outer surface of the next adjacent segment portion and to be adhered thereto by heat and pressure, and the inner coated face of each pleat being adapted to areaeea be folded over in direct contact with the corresponding inner coated surface of the next adjacent segment portion and adhered thereto by heat and pressure.

3. A cap for bottles and other containers formed of a light foldable sheet material, a coating of thermoplastic composition on the inner face of said cap adapted to be placed in contact with the mouthof a container, said cap having a central mouth covering portion and a skirt portion, a series of spaced extending fold lines in said skirt portion adapted to enable same to form a series of segments and connecting pleats, the outer extremity of each segment being cut to provide a' continuous circular line when the cap is sealed in position, the lower end portion of said pleats being cut to form notches thereby permitting a portion of the inner coated face of each segment to be folded over in direct contact with the corresponding portion of the outer surface of the next adjacent segment portion and to be adhered thereto by heat and pressure, and the inner coated face of each pleat being adapted to be folded over in direct contact with the corresponding inner coated surface of the next adjacent segment portion and adhered thereto by heat and pressure.

4. A cap for bottles and other containers formed of a light foldable sheet material, a coating of thermoplastic composition on the inner face of said cap adapted to be placed in contact with the mouth of a container, said cap having a central mouth covering portion and a skirt portion, a series of spaced substantially radially extending fold lines in said skirt portion adapted to enable same to form a series of segments and connecting pleats, leader pleats positioned at the inner end portions of each segment, the lower end portion of said pleats being cut to form notches thereby permitting a portion of the inner coated face of each segment to be folded over in direct contact with the corresponding portion of the outer surface of the next adjacent segment portion and to be adhered thereto by heat and pressure, and the inner coated face of each pleat being adapted to be folded over in direct contact with the corresponding inner coated surface of the next adjacent segment portion and adhered thereto by heat and pressure.

SERENUS H. A. YOUNG.

substantially radially 

